Those extra zeros means the barrel's gotta be at least half a mile thick around the chamber.

I think a few of our friends here shooting 7 rem's might be over 100 KPSI with some of their stuff. A hammer is not an acceptable tool for opening a bolt even when it says MAG. on the side of the barrel.
I think you would have a tough time getting any lead core bullet to survive 65,000 KPSI; it'd take a low friction monolithic of some sort.

I recently began shooting long range, and I took my gun to a gunsmith to get a muzzle brake on it. The guy immediately started bragging about his custom made long range rifles. I told him that i would be interested in one in the future.

He then started to say that his guns can reach 4000 fps in a 7mm STW with a 140 grain bullet. Is this possible or is he full of it? he says that his loads are "not in the books."

Thank you

1. He is correct, he can do it ONCE! But I would be standing waaay back when he shows you and have 911 on speed dial.

2. Find another smith immediately, this one is crazier than bat shxxt and you do not want to use to even put on a recoil pad.